Am i a moron?

Orcs must die deathtrap. Amazing solo run going great 40+ rift points steady all levels then boss level comes and out of nowhere all my barricades start getting annihilated my killbox and all my resources wasted on a corner of the map and i lost 1000 skulls Im PISSED WHAT THE FUCK.

What are the rules here is it any bossfight barricades dont matter? Just a fluke? Should i plan for this everytime and just surround my rift with barricades?